Radiation In Space Could Be Harmful to Far-Travelling Astronauts

Radiation in Space Could Be Harmful to Far-Travelling AstronautsMay 12, 2017

Star Trek makes it look so easy. In that universe, one can conquer physics by travelling at faster-than-possible warp speed, beat computing and math by disintegrating someone at one point and building them back up at another, and surpass laws of thermodynamics with phaser beams.

Real space travel, however, is extremely difficult. It’s time consuming, energy intensive and dangerous. On Star Trek, they can fly to Mars in minutes. The journey would take us more than a month, and while the crew of the Enterprise always seems to weather the journey just fine, long-term space travel could have profound health effects on our astronauts.

Researchers from Wake Forest Baptist Medical Center are working with NASA scientists to learn how space travel will impact human health. According to a new study they published in the journal Leukemia, the radiation astronauts would experience over the course of a journey to Mars could deplete their immune systems and potentially cause cancer.

Studies like this one highlight the challenges of travelling through space, but could provide the knowledge that astronauts need to explore the rest of the solar system and eventually beyond.

Earth’s atmosphere and magnetic field are able to block two types of radiation called galactic cosmic rays and solar energetic particles. They aren’t concentrated or powerful enough to scorch someone in seconds, but the researchers found that prolonged exposure can damage and mutate cells.

Scientists at the Brookhaven National Laboratory in New York bombarded human hematopoietic stem cells (HSCs) with radiation that would mimic a journey to Mars, then sent the cells to Wake Forest for analysis. HSCs are the cells responsible for making most of the cells in our blood, both red and white. The Wake Forest researchers found that the HSCs lost between 60 and 80 percent of their ability to make blood cells.

Not only could this cause anemia, but the lack of healthy immune white blood cells could cause astronauts’ immune systems to struggle in space.

When these irradiated HSCs were put into mice, some of the cells began dividing at a rapid, uncontrollable rate, and the results resembled acute lympoblastic leukemia, a blood and bone marrow cancer that arises from mutated white blood cells.

The researchers found that these cancers could be extra deadly because the blood cells that would normally fight off these cancers, the white blood cells, are already depleted from the radiation.

Radiation is just one health problem in space that NASA researchers are trying to solve. The lack of Earth-like gravity also suppresses the immune system and leads to a loss of bone density. There are psychological barriers to consider as well, like being confined to a small space with very few if any people for months at a time.

We cannot travel like they do on Star Trek yet, but studies like this could lead to the innovations that protect our astronauts until we can.

—Daniel Lane

Daniel Lane covers science, medicine, engineering and the environment in North Carolina.